Improvement in alloy for coin



UNITED STATES PATENT OFFICE;

\VILLIAM IVHEELER HUBBEIiL, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN ALLOY FOR com.

Specification fonning part of Letters Patent No. 209.263, dated October22, 1878; application filed February 7, 1878.

To all whom it may concern:

Be it known that I, WILLIAM WHEELER HUBBELL, ofPhiladelphia,Pennsylvania, have invented a new and useful Improvementin'the Metal Alloy for Commercial Coin for which Letters Patent weregranted to me May 22, 1877, No. 191,146, and the following is adescription thereof:

In the patent of May 22, 187 7 the minimum ratio of proportion is twentyof silver to one of gold. The standard of fineness is ten-elevenths. Thedensity of pure silver is 10.51. The proportions are not adapted tometric measure. In this improvement the minimum is fourteen and themaximum is twenty of silver to one of gold, and the gold and silver bothin metric measure. The standard of fineness is nine-tenths and thedensity about 11.02 when subjected to the highest coinage pressure,under which it increases more than other alloys. The standard ofproportion is 16.1 to one (1) as the best.

The improvement consists in the proportions of component metals of gold,silver, and copper to increase the density, when finished into coin,above that of pure silver.

The improvement is also adapted to metric measure or weight of coin, aswell as troy measure, and to the standard of nine-tenths fineness of themass of precious metals of gold and silver. The proportions areseventy-five (75) grams in weight of pure gold, one hundred andforty-two and a half (1412.5) grams in weight of pure copper, and twelvehundred and seven and a half (1,207.5) grams in weight of pure silver,sufficient to make one hundred dollars.

To enable others to make and use my invention, I declare the followingto be a full and sufficient description thereof.

I melt the metals separately and pour them together, stirring andmixingthem thoroughly; or I melt and mix the silver with its proportionof the copper and the gold with its proportion of the copper, the copperforming one-tenth of the whole weight. Then mix them all thoroughlytogether, cast into ingots, roll into strips, and anneal them. I immersethe strips in muriatic acid for about ten minutes, take them out andexpose them to the airuntil they are dry, or about two hours. Then placethem in a strong solution of ammonia or of muriate of ammonia, or both,dissolved in water-that is, about one pound of either or half a pound ofeach dissolved in one gallon of water; or the strips or metal may beimmersed in sulphuric acid exposed to the air, and then in a solution ofmuriate of ammonia and water, or in the latter solution alone. I removethem from the ammoniated bath in about one hour, and rub and clean themoff with whiting and buckskin or woolen cloth, or wash in water and drythem in sawdust. Atoms of the silver color will have been removed. Thesurface of the coin metal will be an alloy chiefly of gold and copper ofa peculiar golden color, by which this coin metal may be distinguishedfrom either gold or silver or base metals, as well as by its greaterdensity and more prolonged clear ring or sonorous vibrations. This isdue to the nature of the alloy. Of this alloy, in the proportionsdesc1ibed,a metric dollar of one hundred cents value, fourteen and aquarter grams in weight, or two hundred and nineteen and nine-tenthsgrains in weight, finished, will contain seven and a half decagrams ofpure gold, fourteen and a quarter decagrams of pure copper, and onehundred and twenty and three-quarters decagrams of pure silver, on aratio of valuation of sixteen parts of silver as equivalent to one partof gold, and exhibit an alloy color of the gold and copper chiefly, andwill be of a density above pure silver, and next to that of gold coin.

When the strips are rolled out and the surfaces finished as described,cut them into planchets and strike up the planchets into coin for use asmoney by means of a coin-press and suitable dies.

The density of this alloy increases under coinage-pressure much morethan the density of silver and copper increases, and is above that ofpure silver, and it cannot be counterfeited in density or color.

These proportions may be slightly varied. The gold may be increased asto the silver as one ofgold is to fourteen of silver, and be decreasedto stand as one of gold isto twenty parts of silver in weight, thecopper to remain at one-tenth of the whole mass, and the density remainabove pure silver within these proportions. The proportions first heroinstated are thousand and seventy-five (12,075) parts of silver, and onethousandfourhundred and twentyfive (1,425) parts of copper,substantially as the best in all respects for density, weight, value,and color for coin, particularly of metric measure, for dollars, halves,quarters, and

dimes. described.

What I e1aim.is WM. WHEELER HUBBELL. The alloy coin metal of gold,silver, and Witnesses:

copper, in or about the proportions of seven E. W. GRANT,

hundred and fifty (750) parts of gold, twelve JAMES H. HOUSTON.

